DIY web site Instructables details how to keep your plants healthy by building a self-watering planter from a couple of plastic IKEA storage boxes. The concept is simple. Two boxes are nested inside one another; the bottom box holds the water, and wicks made from string carry the water into the top portion, where the soil and plants live. All you need to do is make sure the bottom portion has enough water, and the rest should take care of itself. If your forgetful green thumb tends to turn things brown, this self-watering planter might be the perfect project. If you're looking to go really advanced, check out how to build an automated drip watering system.